A Bibliometric Analysis Concerning Local Ecological Knowledge on Elasmobranchs and Chimaeras

The absence of historical data on endangered species poses a conservation and socio-environmental problem. Approximately one-third of all Elasmobranchs and Chimaeras are under some level of threat of extinction, with knowledge gaps for many species. This research aims to conduct a biliometric analysis of scientific production concerning Local Ecological Knowledge (LEK) of Elasmobranchs and Chimaeras. Searches on the subject were carried out at the SciELO, Scopus and Web of Science databases. The retrieved publications were assessed and sorted by a list of inclusion criteria, totaling 120 articles. The findings indicate that studies on LEK applied to Chondrichthyes assessments have recently gained relevance. The studies were published in a wide variety of journals and by researchers from different countries. Most research focused on marine ecosystems and interviewed professional fishers. Of the 179 Elasmobranchs species studied, most are large sharks with conspicuous diagnostic characters, such as Galeocerdo cuvier , Isurus oxyrinchus and Sphyrna lewini , mainly in publications focused on fisheries. Studies addressing ethnoknowledge as a historical data collection source are undoubtedly paramount, and the need for further investments in this research field in countries with scarce data addressing other actors, themes and scarcely studied taxa, is clear.


INTRODUCTION
Absence of historical data for threatened and fished species constitutes a large-scale environmental problem.In this regard, access to anecdotal, historical, and multicultural records has become a valuable tool in recovering the ecological history of several taxonomic groups, such as corals, groupers, cetaceans, and elasmobranchs (Ferretti et al. 2008;Fogliarini et al. 2022;Martínez-Candelas et al. 2020;McClenachan et al. 2012;Santos et al. 2022).This has altered societal perceptions of biological and ecological species aspects and may aid in future conservation decision-making (Ferretti et al. 2008;Fogliarini et al. 2022;McClenachan et al. 2012).In this context, Local Ecological Knowledge (LEK), comprising a set or system of theoretical and practical knowledge based on environmental observations and experimentations is an alternative source of information (Berkes et al. 2000;Ruddle 2000) and a way to access historical narratives (Burns et al. 2020;McClenachan et al. 2012).
Ethnoichthyology, "from the Greek 'ethno', race or people + 'ichthys', fish + 'logos', discourse, study" (Marques 2012) is the field that studies the Local Ecological Knowledge (LEK) associated with fishes and their many uses (Bahuchet 1992).Although this term has been employed by researchers since the late 1960s, this field of knowledge is still neglected by science (Albuquerque et al. 2021;McClenachan et al. 2012;Narchi et al. 2014).Despite this, research has revealed the potential of this field in contributing to the theoretical and practical advancement of biology and related areas, such as anthropology, during their implementation, providing an overview of interactions between fauna and different human groups (Albuquerque et al. 2021;Pinto et al. 2018;Ruddle 2000;Silvano and Valbo-Jørgensen 2008).
The class Chondrichthyes comprises sharks and rays (Subclass Elasmobranchii) and chimeras (Subclass Holocephali), an evolutionarily successful fish group (Dulvy et al. 2021;Stein et al. 2018).Representatives belonging to this class display a variety of body and behavioral patterns, are globally distributed throughout many aquatic environments, and play important ecological roles in maintaining ecosystems (Ebert et al. 2021;Ferretti et al. 2008;Sherman et al. 2023).Most sharks, rays and chimeras display intrinsic characteristics, such as slow growth rates, late sexual maturation, and low fecundity (Dulvy et al. 2017;Lucifora et al. 2022) which added to the chronic threats directed at this group, such as overfishing, habitat degradation and pollution, contributing to their decline (Dulvy et al. 2017;Lucifora et al. 2022).It is, in fact, currently estimated that about 33% of Chondrichthyes are at risk of extinction (Dulvy et al. 2021;Sherman et al. 2023;Stein et al. 2018).
Knowledge synthesis studies have been carried out focusing on Elasmobranchs and Chimaeras, highlighting a significant lack of data and the need for new techniques and methodologies to study the species belonging to this taxon (e.g., Moura and Vianna 2020), emphasizing LEK research (Becerril-García et al. 2022;Cashion et al. 2019;Coelho et al. 2021;Jorgensen et al. 2022).Considering human and Chondrichthyes interactions, access to LEK information becomes a valuable source of historical data and reveals the importance of this taxon in human relationships (Bastari et al. 2022;Mojetta et al. 2018).Furthermore, access to these data reinforces their importance, especially in countries with limited research resources and investments, which is clearly demonstrated by knowledge gaps for several species (Blanco-Parra et al. 2022;Ruddle, 2000;Seidu et al. 2022).
Bibliometric research plays an important role in providing an overview of the state of knowledge of a certain subject, identifying patterns, trends, gaps and indicating directions for future studies (Albuquerque et al. 2013;Alves et al. 2018;Moura and Vianna 2020;Santos and Vianna 2017;Souza and Vianna 2020).To this end, a worldwide bibliometric analysis was conducted on LEK focused on Chondrichthyes species, aiming to answer the following questions: (i) what is the temporal trend concerning LEK publications focused on Chondrichthyes species?, (ii) where was this research been developed?, (iii) which are the most representative taxonomic groups reported in these surveys?and (iv) what topics have been addressed by these surveys?

Data collection
Searches were carried out at the following databases: SciELO, which indexes articles published in regional Latin American journals (Souza and Vianna 2020); Scopus, which covers more than 16,000 publications (Martín-Martín et al. 2018;Vieira and Gomes 2009), and Web of Science, considered the most complete scientific literature database, indexing publications from 1945 to the present (Santos and Vianna 2017;Souza and Vianna 2020).The research period was set from 1945 to October 10, 2022.
The searches were carried out in the "Topics" section, which covers titles, abstracts, and keywords.The choice of keywords and Boolean operators followed Moura and Vianna (2020), where two search fields joined by the "AND" operator were used in the article searches.The symbols "*" and "$" contemplate variations of up to one letter, and the second, of more than one letter.The symbols "$" and "*" were used to guarantee the variety of spellings that the compiled terms may present.The first search field refers to the knowledge area, comprising the string "ethno*" OR "ecological knowledge" OR "local knowledge" OR "traditional knowledge" OR "fish* knowledge" OR "folk knowledge" OR "interview".The second concerns Chondrichthyes, set as "chondricht*" OR "elasmobran*" OR "shark$" OR "ray$" OR "stingray$" OR "skate$" OR "holocepha*" OR "chimaerifor*" OR "chimaera$".All keywords were also translated into Portuguese and Spanish.A third search parameter comprising the keywords "ethnology" OR "x-ray", joined by the operators "NOT" or "AND NOT", was added in order to exclude publications from unrelated topics.
For the SciELO database, the keywords applied to the three search fields were used separately (i.e., "ethno* AND shark*" AND NOT "ethnology"), due to the simplicity of the platform's search algorithm and the size of the database, which does not retrieve publications when applying complex word combinations (Souza and Vianna 2020).

Data analysis
Article inclusion criteria were set as follows: (i) interviews as one of the applied methodologies; (ii) focus on one or more Elasmobranchs and Chimaeras species, describing their taxonomic level (order, family, genus and/or species); and (iii) availability in Portuguese, English or Spanish.
After screening, the retrieved articles were compiled in a database and were classified according to title, author(s), publication year, journal, database, language, study area, presence/absence of protected area, human group(s) (Table 1), ecosystem (fresh-water, estuarine, marine), taxonomy (order, family, genus, and species), focus on Chondrichthyes, conservation status (IUCN), and addressed topic(s) (Table 2).The titles, abstracts, methodologies, and results sections were evaluated for data retrieval.Only data obtained from interview methodology results were considered.
Taxonomic corrections for family, genus, and species were applied according to the Eschmeyer Catalog of Fishes (last updated on 11 January 2023), Gomes et al. (2019) for orders occurring in Brazil, and Nelson et al. (2016) for orders with no records in Brazil.Furthermore, regarding preliminary taxonomic identification of species (confer, "cf."), the species mentioned by the authors were considered in our study.For groupings of species with two epithets, separated by the symbol "/", only the genus was considered.
The data were compiled in a spreadsheet editor program, synthesized, and presented in the form of graphs generated by the R software (R Core Team, 2023), using the "ggplot2" and "piedonut" packages.The distribution map of total publications by country was generated using the Quantum GIS Software (QGIS 3.10.11),with the shapefile format obtained from Eurostat (2023).The species taxonomy graph was generated in Microsoft Excel.A weighting was performed to enable comparative analysis for the determination of human groups, ecosystems, themes, sub-themes, and taxonomic groups, assigning a greater proportional weight according to the number of human groups, ecosystems, themes, subthemes, and taxonomic groups studied in each evaluated article.

Bibliometrics
A total of 120 articles on LEK concerning Chondrichthyes species were retrieved from the three searched databases from 1945 to 2022.Article publication years were restricted from 1996 to 2022 (Figure 1; Additional File 1).The number of publications per year from 1996 to 2010 remained low, not exceeding three articles in 2007.Articles were published only 1996, 2000, 2007 and 2009, with gaps between 1997 and 1999, between 2001 and 2006 and 2008.From 2011 onwards, the number of publications increased, surpassing three publications per year, except in 2012, 2013 and 2015.A substantial increase in the number of publications is noted from 2016 onwards, with a peak of 19 articles observed in 2021.
Articles retrieved from the Scopus database covered most publications (n= 110; 92%), followed by the Web of Science, (n= 78; 65%), and SciELO (n= 3; 3%) databases.However, redundancies between the searched databases were noted, with three articles retrieved by all three databases, and 65 (54%) retrieved both in Scopus and Web of Science databases.
The retrieved articles were published in 56 different journals (Table 3).The Aquatic Conservation and Marine and Freshwater Ecosystems journal published the largest number of articles (n= 14; 12%), followed by Marine Policy (n= 12; 10%), and Biological Conservation (n= 6; 6%).It is noteworthy that, of the total number of journals observed in our review, only five focus on relationships between humans and other elements of nature, namely Journal of Ethnobiology and Ethnomedicine (n= 5), Ethnobiology and Conser-vation (n= 3), Ethnobiology Letters (n= 2), Conservation and Society and Ecology and Society (both with only one article).In addition, of the total number of retrieved articles, most (n= 117; 98%) were published in English, with only two (2%) articles published in Spanish and one (1%) in Portuguese.

Human groups
The most interviewed human groups were fishers, with 97 (56%) publications, followed by community members and traders, with 19 (11%) publications each, and divers with 15 (9%) publications.Although the "Others" category was noted in a high number of publications (n= 12; 7%) compared to other categories, such as Researchers (n= 6; 3%), Government (n= 2; 1%) and Health agents (n= 2; 1%), the groups that fit into this category present values equal to and/or lower than those concerning the Government and Health agent categories.Legend: The symbol "*" indicates journals related specifically to relationships between humans and other elements of nature.

Species
A total of 179 species included in the Elasmobranchii were mentioned by the retrieved articles (Table 4).Out of the 120 publications found, the majority (n= 93; 77.5%) focused on Elasmobranchs.The three most studied species were Galeocerdo cuvier (tiger shark) in 24 (20%) publications, Isurus   the most cited genera, Carcharhinus and Sphyrna, both mentioned in 46 articles (corresponding to 17.2% and 9.5% of studied taxa).A total of 51 articles restricted information to the genera level, 16 to family and three to order.No articles mentioned the Holocephali subclass.
The 10 most cited species are included in three threat categories -Vulnerable (VU), Endangered (EN) and Critically endangered (CR) -, except for Galeocerdo cuvier, which is considered Near Threatened (NT) (Table 4).In the overall picture, of the 179 species mentioned in the articles, 126 (70%) are included in some threat category (Figure 5).No Extinct (EX) and Extinct in the Wild (EW) species were mentioned, and only Potamotrygon boesemani is not categorized by the IUCN due to lack of data.

Thematic areas
The retrieved publications addressed different topics within four main themes, namely Biology, Conservation, Fisheries and Human Relations (Figure 5).Both themes and subtopics presented results classified in more than one category.The most discussed topic was Fishing, with 88 (30%) publications.Data on fishing gear was the most mentioned among the subtopics related to this area, noted in 78 (30%) publications, followed by economy, 49 (19%) and fisheries impacts, 34 (13%).
Information on biology aspects of mentioned species ranked as the second most cited topic, comprising 80 (27%) publications.Species habitat was the most discussed subtopic, present in 42 (27%) publications, followed by ethnotaxonomy (n= 37; 23%), food (n= 24; 15%), and behavior (n= 21; 13%).Regarding conservation, 67 (23%) articles were identified, with environmental changes comprising the most discussed sub-theme, reported in 60 (74%) publications, followed by management and legislation (n= 21; 26%).Other human relationships, excluding fishing, were addressed in 60 (20%) publications, with human food being the most cited subtopic, (n= 42; 42%) articles, followed by other subtopics (n= 19; 19%), and medicinal uses (n= 16; 16%).The results indicate that studies employing LEK to investigate sharks and rays has only gained relevance very recently.These surveys have been published in a wide variety of journals and were conducted in different countries.The studies mostly focus on the marine environment and the interviewed public gen-erally comprises professional fishers.Many species are cited, but most are large sharks with conspicuous diagnostic characters, with a recurring fishing theme.

Bibliometrics
The biliometric analysis carried out herein indicates a slow but steady increase in publications focused on LEK regarding Chondrichthyes, restricted, however, only to the Elasmobranchii Subclass, in comparison to the general scientific production observed for this group (Oliveira et al. 2023).This increase was noted mainly in the last decade, a reflection on the increasing number of articles published in the ethnozoology field (Albuquerque et al. 2013;Alves et al. 2018), and consequently in its subareas, such as ethnoichthyology, which has been accompanying this growth (Ladislau et al. 2021;Lyra-Neves et al. 2015).
Compared to other ethnobiology areas, ethnozoology and its sub-area ethnoichthyology are recent study fields.The term ethnoichthyology was employed for the first time in 1967 (Morril 1967).The field was then finally established in the 1990s, when a significant increase in the number of publications focused on ethnobiology was noted, mainly concerning ethnozoology, added to research training diversification on the subject (Alves et al. 2018;Aswani et al. 2018;Marques 2012).However, according to our data, the increasing assessments in the ethnoichthyology field focusing on Chondrichthyes is even more recent, taking place only after 2016.
Despite the number of articles retrieved in this review, it is important to emphasize that this research does not consider all existing publications, as the applied methods and criteria to search for publications on LEK focusing on Chondrichthyes are limited.Furthermore, although an overlap was noted for the Web of Science and Scopus databases, both do not cover a variety of journals, especially those related to multidisciplinary areas and/or to society (Halevi et al. 2017;Martín-Martín et al. 2018), restricting most publications to the English language (Halevi et al. 2017;Martín-Martín et al. 2018;Smith et al. 2021).In addition, many ethnozoology articles were published in journals with low impact factors or not indexed and related to other biology fields (Gutiérrez-Santillán et al. 2019;Lyra-Neves et al. 2015), making article retrieval difficult when applying the search criteria employed herein.
The number of publications retrieved in this systematic review certainly reflects environmental and sociocultural issues that have taken place over the last few years in several countries, leading to LEK losses, either due to the difficulty in interacting with LEK resources, abundance decreases, or departure of people from professions and/or communities (Alves and Nishida 2003;Pinto et al. 2018;Svanberg and Locker 2020).Furthermore, the inherent difficulty in obtain-ing quality data due to the lack of trust established between interviewees and researchers must also be considered (Alves and Souto 2011).This mistrust situation can be aggravated by legislations that restrict and apply penalties to those who use Chondrichthyes resources, especially endangered species (e.g., Lyra-Neves et al. 2015), which is the case of most Elasmobranchs and Chimaeras species.

Geographic distribution
Research on LEK concerning Elasmobranchs has been carried out in several countries displaying multiple sociocultural and economic realities.Several factors may contribute to lesser or greater research in the ethnoichthyology field, such as the faunal diversity and variety of social actors that use these resources (Alves et al. 2018;Nunes et al. 2021), the absence or scarcity of past fisheries and species biology data (Jorgensen et al. 2022;Santana-Morales et al. 2020;Skubel et al. 2019), and public investment in higher education and research institutions (Albuquerque et al. 2013;Alves and Souto 2011;Alves et al. 2018;Shiffman et al. 2020).In this regard, Becerril-García et al. ( 2022) carried out interviews with specialists on the future perspectives of Chondrichthyes research and demonstrated that, for 90% of the interviewees, the main factor that affects the progress of scientific production in Latin America compared to the global context is lack of funding.However, despite fitting into all these factors, Brazil ranked first concerning publications focused on elasmobranch ethnoknowledge, corroborating the country's international recognition for scientific ethnozoology and elasmobranch production (Alves et al. 2018;Lyra-Neves et al. 2015;Shiffman et al. 2020) and demonstrating that Brazilian researchers use ethnoichthyology as a low-cost tool to retrieve fisheries data based on traditional knowledge, as a way to compensate for the absence of official historical series, the low funding and baseline data.
Despite what was observed for Brazil, and although research in ethnoichthyology is being developed in other countries, publications are still scarce, and several authors increasingly emphasized the need to intensify studies in this area, given the importance of fishing and fish in various forms of cultural manifestations, the absence of historical data associated to their use and the significant knowledge gaps on species biology and ecology.This has been noted for some American countries, except for Brazil (Alves et al. 2018;Aswani et al. 2018), as well Europe (Alves et al. 2018;Ferretti et al. 2008;Svanberg and Locker 2020); Africa (Aswani et al. 2018;Seidu et al. 2022), Asia (Alves et al. 2018;Haque et al. 2021) and Oceania (Alves et al. 2018).It is also important to note the increasing number of publications and countries, most considered "developed", which have been producing research focused on other knowledge areas concerning elasmobranchs (Oliveira et al. 2023).
Our results when evaluating ethnoichthyology in a broad manner indicate that most research was carried out in marine ecosystems, as reported by Ladislau et al. (2021).This reflects the number of Elasmobranchs and Chimaeras species that occur in these environments, as most species are exclusively marine, although part of part of their life cycles may take place in estuarine environments (Ebert et al. 2021 2017), which can be found in estuarine and eventually freshwater environments.However, few of the articles retrieved here focused on freshwater environments.According to Junqueira et al. (2020), research in this area is costly, requires long travel times (sometimes with access only by waterways) and present difficulties in communication and in material transport.This makes the low knowledge production on freshwater elasmobranchs worrying, due to late sexual maturation, low fertility, high endemism, and territorial restrictions (Abell et al. 2008;Dulvy et al. 2017;Lucifora et al. 2019Lucifora et al. , 2022)).Furthermore, general elasmobranch threats (overfishing, habitat loss, urbanization, pollution, among others) are more significant for freshwater elasmobranchs, mainly tropical and subtropical species (Barrowclift et al. 2023;Lucifora et al. 2019).This accounts for most data deficient elasmobranchs as classified by the IUCN occurring in freshwater (Dulvy et al. 2017).
Although few articles have been conducted in protected areas, studies indicate that these areas are important for elasmobranch conservation (Jorgensen et al. 2022;Shiffman et al. 2020), and may favor ethnozoology studies (Alves et al. 2018).Certain conservation unit types, however, such as Marine Protected Areas, are under fishing restrictions (Jorgensen et al. 2022;Sabadin et al. 2022), which may be associated to conflicts of interest between conservation and exploitation, directly influencing the willingness of fishers to collaborate in interviews and, consequently, making research difficult (Alves and Souto 2011).

Human groups
Fishers were the most approached group concerning elasmobranch research.In fact, the traditional empirical knowledge of this group has been applied for years to obtain and complement biological and ecolog-ical data, in addition to accessing temporal abundance trends and serving as a basis for management strategies (Bastari et al. 2022;Giglio and Bornatowski 2016;Sáenz-Arroyo and Revollo-Fernández 2016;Santos et al. 2022;Silvano and Valbo-Jorgensen 2008), as fisher knowledge is a result of the proximity and regularity of fish interactions (García-Quijano and Pitchon 2010; Marques 2012; Pinto et al. 2018).As noted by Ladislau et al. (2021), although fisher knowledge is paramount in ethnoichthyology studies, other actors should be included in this line of research, in order to access the knowledge and perceptions of other actors who interact with ichthyofauna as much as fishers (Pinto et al. 2018;Skubel et al. 2019).Several examples illustrate how other social groups can contribute to a better understanding of the dynamics that encompass people-fish relationships.For example, Nunes et al. (2021), in Brazil, indicate that women who work in fish processing may possess knowledge on fish diet and reproduction aspects.In another study, Lopes et al. (2021) demonstrated temporal changes in the stocks of several fish species by interviewing family nuclei in fishing communities in São Paulo, Rio de Janeiro and Santa Catarina (Brazil) and divers interviewed by Blanco-Parra et al. (2022) in Mexico, demonstrated elasmobranch abundance declines.
Carcharhiniformes is the largest shark order, comprising 10 families and about 291 species (Ebert et al. 2021;Gomes et al. 2019), which explains the higher number of citations for this order in the retrieved articles.However, even though the Carcharhinidae family and Carcharhinus and Sphyrna genera were the most cited, they are not the most numerous species among sharks (Ebert et al. 2021;Gomes et al. 2019).They include however, taxa with wide geographic distributions, close to the coast, are found in different environments, are large and display striking morphological characteristics (Ebert et al. 2021;Gomes et al. 2019;Oliveira et al. 2023).Furthermore, the variety and intensity of the ways in which elasmobranchs interact with humans also comprise a crucial factor in generating knowledge on this group.In addition to fishing, these species can also interact with people during recreational activities (Blanco-Parra et al. 2022;Cisneros-Montemayor et al. 2020) through injuries and accidents (Chapman and McPhee 2016; Silva et al. 2020;Katzer et al. 2022), by feeding (Davidson et al. 2016;Giglio et al. 2018) and through culture and/or religion expressions (Grant et al. 2021;Leeney and Poncelet 2015;Stacey et al. 2012;Torrente et al. 2018;Valerio-Vargas and Espinoza 2019).New knowledge and perceptions about species are, in fact, formed from these different forms of interaction.
Among the species mentioned in the publications retrieved by this systematic review, 126 (70%) are included in endangered categories (VU, EN, CR).If we consider that the two species classified as Data Deficient (DD) also mentioned in the publications are in fact threatened (Dulvy et al. 2021), the number of endangered species increases to 128 (72%).Therefore, ethnoichthyology also comprises a valuable way to generate data to support assessments on extinction threats in elasmobranchs, as about 33% of all Elasmobranchs and Chimaeras species are included in some threat category, according to IUCN assessments (Dulvy et al. 2021, Leduc et al. 2021;Oliveira et al. 2023).Only Potamotrygon boesemani is not categorized, probably due to its small occurrence area (Rosa et al. 2008), which, coupled to logistical factors, can restrict biology and ecology assessments for this species.
Despite the high number of publications retrieved herein and the reported diversity of fishing gear and fishing modes, no Chimaeras species were mentioned.One research effort has been, in fact, carried out by Baremore et al. (2021) with fishers from Mexico, Belize, Guatemala and Honduras, using photographs and popular names (Additional File 1) to gather data on Neoharriotta carri (Dwarf sicklefin chimera).The main reason for the absence of mentions for these members is probably related to biological aspects, such as low frequency and deep-water occurrence (Didier et al. 2012).Holocephalans, however, are known to interact with fishing, although infrequently, and species can be grouped upon landing along with shark species, due to generalizations concerning their external morphology, termed generically as dogfish or cação, as shark meat is called in many countries, or even discarded, losing this information (Di Dario et al. 2011;Didier et al. 2012;Santana-Morales et al. 2020).

Thematic areas
Ethnoichthyology is a multidisciplinary knowledge area (Alves et al. 2018;Marques 2012;Narchi et al. 2014) focusing on various topics.The first forms of interaction between people and elasmobranchs were and still are through fishing by groups that live close to aquatic environments (Lopes et al. 2016;Mojetta et al. 2018;Pinto et al. 2018).This justifies the predominance of fishing as the most addressed topic, as it comprises a primary and regular source of interaction (Berkes et al. 2000; García-Quijano and Pitchon 2010).In addition, fishing demonstrates its importance and produces knowledge not only through labor activity, but also through traditional people identity and culture maintenance (Skubel et al. 2019).
Elasmobranch use as human food is noteworthy among the themes addressed by human-elasmobranch relationships in the retrieved publications.In fact, sharks and rays are a dietary component in several coastal and/or developing countries, mainly due to the guarantee of food security in its broad spectrum, which includes protein provision, with fish considered a healthy food and generating income from commercialization, allowing for the purchase of other food inputs and the settlement of other expenses (Davidson et al. 2016;Dulvy et al. 2017;Giglio et al. 2018;Skubel et al. 2019).In addition to the value of these animals as a food and income source, elasmobranchs are also important in therapeutic and religious uses, through their consumption and/or topical use of animal parts or by-products.For example, teeth or parts of sharks are used as a medical tool and for cultural purposes, as noted by Rasalato et al. (2010) for Fiji and Leeney and Poncelet (2015) for Guinea-Bissau, while the head of Pristis pristis is used in the prevention of headaches, baldness and its teeth to obtain calcium and in the preparation of energy drinks in Costa Rica (Valerio-Vargas and Espinoza 2019).Several species of sharks and rays are employed by fishing communities due to their antiasthmatic and antiinflammatory potential, and for cholesterol control, among others (e.g., Tocantins, Brazil, Begossi and Braga 1992; Península de Paria, Venezuela, Fariña-Pestano et al. 2011).In contrast, records of permanent or periodic restrictions on the consumption of these animals are associated to health maintenance, for example, for injured people, pregnant women and women in the puerperium, among other conditions (Begossi et al. 2004;Grant et al. 2021;Ramires et al. 2012).These uses highlight the sociocultural relevance of elasmobranchs for coastal and riverside communities, who also use these animals for tourism (Cisneros-Montemayor et al. 2020), for ethnic group identification through totem poles and/or scarification (Grant et al. 2021;Torrente et al. 2018), and in crafts and tools (Rasalato et al. 2010;Valerio-Vargas and Espinoza 2019).
The importance of the human dimension in elasmobranchs conservation is of recognized importance in academia (Booth et al. 2019;Oliveira et al. 2023;Ostrovski et al. 2021;Skubel et al. 2019).However, as noted, few studies aim to investigate the knowledge and perception of actors who interact directly with these animals.Furthermore, what makes this issue more sensitive is the problem of non-inclusion of local actors and their respective contributions in decision-making processes (Johannes et al. 2008;Ostrovski et al. 2021;Pinto et al. 2018;Renck et al. 2023;Skubel et al. 2019), in addition to establishing a simple and objective dialogue on the subject.
Elasmobranch conservation is a topic of different opinions.For example, there are those who relate conservation successes to country development levels by employing development indices (Lucifora et al. 2019) and the "emotional affinity" of people towards these animals, thus influencing management and fisheries resources management (Skubel et al. 2019;Ostrovski et al. 2021).In addition, behavioral and cultural changes may also take place, ignoring the history of exploitation between countries as a strategy to reduce or end elasmobranch capture (Booth et al. 2019;Lucifora et al. 2019).Counterbalancing these ideals that tend to homogenize and generalize issues associated with elasmobranch conservation to society, some coastal communities present cultural and/or religious expressions that aid in species conservation.For example, Prionace glauca is called the shark god (Temago-Purotu or Ma'o-purotu in Tahitian) by Anaa Atoll inhabitants (French Polynesia) and, as a sacred element of this culture, it should not be fished or consumed (Torrente et al. 2018).For the Bajo people (eastern Indonesia), Rhincodon typus captures are prohibited due to laws established by the community's ancestors, as the species is thought to be guarded by a protective spirit which helps fishers in times of adversity (Stacey et al. 2012).These examples reinforce the fact that Chondrichthyan conservation requires a comprehensive approach at the local level considering sociocultural, economic, and environmental factors and involving the main actors affected by the management process (Becerril-García et al. 2022;Ostrovski et al. 2021;Pinto et al. 2018;Renck et al. 2023;Seidu et al. 2022).In this regard, as noted by Diegues (2000), the adoption of generalized management and resource use models are not adequate and effective, as they neglect local particularities.Thus, it is crucial to integrate popular knowledge and the active participation of all involved, in order to make the management process inclusive, participatory, and understandable (Albuquerque et al. 2021;Alves and Nishida 2003;Johannes et al. 2008;Silvano and Valbo-Jørgensen 2008), also comprising a mobilization and social empowerment tool (Alves and Nishida 2003).This will, in turn, contribute to conservation effectiveness, strictly associated with fisheries sustainability, reflecting aquatic environment health and benefitting local economies and cultures.

CONCLUSION
This review demonstrates an increasing trend in the scientific production on LEK directed to Elasmobranchii species in the last decade.Surveys were carried out mostly in Brazil, in marine environments and outside conservation units.This highlights the need to direct research efforts to other countries and freshwater environments, mainly due to the lack of historical information on the biology, ecology and relationships between fish and people, in addition to the threat status of many members of this taxonomic group.
The mention of many endangered species (such Isurus oxyrinchus, Sphyrna lewini, Carcharhinus leucas) highlights research efforts in gathering information in this regard and reinforces the current threat state of many Elasmobranchs and Chimaeras species.In addition, the lack of any Holocephali mentions indicates the importance of exploring other ethnographic methodologies, diversifying interviewed actors, and other less researched taxa like freshwater stingrays, which are potentially more subject to the threats Chondrichthyes are exposed to.
The interdisciplinary ethnoichthyology character was demonstrated herein by the varied actors and top-ics addressed in the retrieved publications.However, other human groups (such as divers, fish processors, health agents, among others) should be included in this type of research.This will allow for further Chondrichthyes knowledge access and information on interactions and issues on rarely addressed topics, such as conservation, which is strictly associated with fishing resource sustainability and maintenance and local cultures that effectively interact with Chondrichthyes.

ACKNOWLEDGMENT
The authors would like to thank Laboratory of Technological and Fisheries Biology (BioTecPesca) students for their collaboration.Thanks are also due to Prof. Dr. Vinicius Fortes Farjalla (VFF) for methodology suggestions, Msc.Aléxia Antonia Lessa da Costa (AALC) who helped with the R script, and Dr. Rachel Ann Hauser-Davis (RAHD) for translating the manuscript.Begossi A, Braga, FMS (1992) Food taboos and folk medicine among fishermen from the Tocantins River (Brazil).Amazoniana.12(1):101-118.
Begossi A, Hanazaki N, Ramos RM ( 2004) Food chain and the reasons for fish food taboos among Amazonian and Atlantic Forest Fishers (Brazil)

Figure 1 .
Figure 1.Annual distribution of publications on Local Ecological Knowledge, concerning Elasmobranchs and Chimaeras, species worldwide from 1996 to 2022.

Figure 2 .
Figure 2. Geographical distribution of publications concerning, Local Ecological Knowledge, on Elasmobranchs and Chimaeras by country retrieved by this systematic review.

Figure 3 .
Figure 3. Orders, families, and genera mentioned by publications addressing, Local Ecological Knowledge, on Elasmobranchs retrieved by this systematic review.

Figure 4 .
Figure 4. Percentage of total species found through Local Ecological Knowledge for Elasmobranchs, by IUCN threat category, retrieved in this bibliometric review.Legend: NE -Not Evaluated; DD -Data Deficient; LC -Least Concern; NT -Near Threatened; VU -Vulnerable; EN -Endangered; CR -Critically Endangered.

Figure 5 .
Figure 5. Topics addressed by publications, on Local Ecological Knowledge, on Elasmobranchs retrieved by this systematic review.

Table 1 .
Description of human groups referred to in Local Ecological Knowledge publications concerning the Class Chondrichthyes retrieved by this systematic review.

Table 2 .
Topics addressed in Local Ecological Knowledge publications concerning the Class Chondrichthyes retrieved by this systematic review.

Table 3 .
Top 10 journals in relation to the total number of published articles, on Local Ecological Knowledge, concerning Elasmobranchs and Chimaeras species retrieved by this systematic review.

Table 4 . List of the 10 Elasmobranchs species most cited by publications addressing, Local Ecological Knowl- edge, retrieved by this systematic review. Classification according to the IUCN Threat Status Categories (2022). CR: Critically endangered; EN: Endangered; VU: Vulnerable; DD: Data Deficient.
; Gomes et al. 2019), with the exception of some stingrays (Potamotrygonidae), restricted to freshwater (Lucifora et al. 2022; Rosa et al. 2008), Carcharhinus leucas (Heupel and Simpfendorfer 2007) and Pristis pristis (López-Angarita et al. 2021; Whitty et al. New records of coastal fishes in the northern Rio de Janeiro State, Brazil, with comments on the biogeography of the south-Whitty JM, Keleher J, Ebner BC, Gleiss AC, Simpfendorfer CA, Morgan DL (2017) Habitat use of a Critically Endangered elasmobranch, the largetooth sawfish Pristis pristis, in an intermittently flowing riverine nursery.Endangered Species Research doi: 10.3354/esr00837.